A conventional display module adopts a structure in which the printed circuit boards are connected on a single side, but the display module with such structure only meets general requirements of display and has relatively poor display effects. With developments of electronic display products, some display devices such as ultra-high-definition display or emerging organic light emitting diode display have their display modules adopt a structure in which the printed circuit boards are connected on multiple sides in order to achieve optimum display effects and meet requirements of high-end functions.